Expand or hide all subfolders while holding a key

If there are a lot of subfolders that someone wishes to explore quickly, there is presently no easy way (that I know of) to expand them all without going through each individual folder to expand its contents.

It would be great if you could hold down shift and click on a subfolders arrow to reveal and expand all subfolders within it.

It could get a bit silly though if there a lot of subfolders, so I'm curious to see what others think.